Sammas
Well-known member
Hey guys!
I recently acquired an MCI JH-600 which I know has rather lacklust preamps. John Hardy has been making retrofit preamps for the 600 based around the 990 opamp which has got me thinking about making my own retrofit based on something more akin to an API preamp.
Here is a link to John Hardy's pre including a schematic - http://www.johnhardyco.com/pdf/MPC600.pdf
It uses a single input transformer and a single 990 opamp with a DC servo.
Ideally, I would love to use a complete 312 circuit but there isn't enough space for the 1.2inch thick output transformer to fit within the channel module. Is it possible to remove the output transformer completely without the addition of a DC servo to sort out the DC offset?
I recently acquired an MCI JH-600 which I know has rather lacklust preamps. John Hardy has been making retrofit preamps for the 600 based around the 990 opamp which has got me thinking about making my own retrofit based on something more akin to an API preamp.
Here is a link to John Hardy's pre including a schematic - http://www.johnhardyco.com/pdf/MPC600.pdf
It uses a single input transformer and a single 990 opamp with a DC servo.
Ideally, I would love to use a complete 312 circuit but there isn't enough space for the 1.2inch thick output transformer to fit within the channel module. Is it possible to remove the output transformer completely without the addition of a DC servo to sort out the DC offset?
